In airbag modules, an airbag is generally placed in a housing, into which it is directly folded. After having been folded, the airbag needs to be permanently fixed because otherwise it would unfold again prior to the attachment of the housing cover.
Another method provides for the airbag to be folded first and then to be prefixed by a suitable textile strap. The prefixed airbag can then be placed in the housing without the risk of unfolding again during the assembly of the airbag module. However, it is a disadvantage of this method that the airbag afterwards may again unfold to the outside between the textile straps unless it is completely enveloped by the textile straps, which in turn would be very expensive.
From EP 1 127 752 B1, a method is known in which the airbag is folded first, then heated and then compressed at the same time being cooled down. Due to the airbag being compressed while being cooled down, the folding of the airbag is supposed to hold up subsequently for a certain period of time without the need for a separate fixation. However, it is a disadvantage of this method that the folding just remains for a limited period of time within which the folded airbag needs to be placed in the airbag module.
It is an object of the invention to provide a method for folding an airbag enabling an improved shape retention of the folded airbag. It further is an object of the invention to provide an airbag module comprising an airbag, which airbag module shall be more cost-effective to produce. Moreover, it is an object of the invention to provide a device by which the folding of the airbag may be improved in so far as the airbag, after having been folded, shows an enhanced shape retention.